Conventional magnetic disk storage drives are highly complex devices that can be sensitive to contaminants. As such, conventional storage drives often contain activated carbon to buffer humidity and to capture organic contaminants that would otherwise disrupt or damage operation of the drives. However, the carbon based adsorbent produces particulate harmful to the operation of the storage drive and thus can require a costly inert barrier membrane (e.g., expanded polytetraflouroethylene or EPTFE type membrane) to prevent adsorbent particles from damaging the operation of the storage drive. The need to encapsulate the solid adsorbent with a particle barrier inhibits the effectiveness of the adsorbent especially to semi-volatile slow moving contaminants.
To remove vapor based contamination, the contaminant must generally first drift to the surface of the protective membrane of the solid adsorbent and diffuse through the membrane before the contaminant can become chemisorbed and bound to the inner adsorbent. This particle barrier inhibits vapor transport to the adsorbent surface. While associated with the surface of the barrier membrane, the contaminant remains free to desorb back into the drive environment. Some storage drives counter the effect of the protective membrane by significantly enlarging the surface area of the carbon based absorbers. However, great cost is associated with the increased surface area of such protective membranes.